Telecommunications systems, cable television systems, and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical fibers comprise thin strands of glass capable of transmitting the signals over long distances with very low loss. Optical networks provide higher capacity and reduced operating costs compared to traditional technologies. Fiber-optic networks may include a system of multiple network components, including switches, routers, converters, modulators, demodulators, etc.
One or more network components may be housed in a server chassis which may, in turn, be mounted in a rack system. A network component may include any equipment designed to be mounted in a rack and may be described as “rack-mount”, “rack mounted”, “rack mount chassis”, or “shelf”. In many cases, the server chassis provides electrical connections for the various components, physical connections between components and/or the rack system, and input/output access for cables, wiring, etc. Some rack systems include at least one shelf configured to receive and connect a variety of plug-in units (PIUs). The shelf may include a backplane providing electrical connections to the PIUs and mechanical features providing physical mounting and/or retaining force for the PIUs.